There was a similar issue a while back, where an open-source system used by a number of CAs was by default configured to generate serial numbers with only 63 bi

There was a similar issue a while back, where an open-source system used by a number of CAs was by default configured to generate serial numbers with only 63 bits of entropy, when the CA/B forum rules require 64 bits: https://www.schneier.com/blog/archives/2019/03/cas_reissue_ove.html https://www.schneier.com/blog/archives/2019/03/cas_reissue_o... This incident was complicated by the fact that it was first noticed while investigating a particular CA (DarkMatter) that was already suspected of various shady activities. Most of the other affected organizations took the incident seriously, fixed the problem and revoked the affected certificates, as required by the letter of the rules, even though the actual risk was small. DarkMatter chose to spend a lot of time complaining and making weaselly arguments on the mailing list (like "a 64-bit number where the leading bit is always zero is still technically a 64-bit random number") which did not do much to convince anyone of their trustworthiness.